Kris%ne(Kras,(M.D.( · 2015. 8. 9. · NeoplasiaOutline(• Tumor(nomenclature(•...
Transcript of Kris%ne(Kras,(M.D.( · 2015. 8. 9. · NeoplasiaOutline(• Tumor(nomenclature(•...
Kris%ne Kra*s, M.D. Neoplasia II: Tumor Characteris%cs
Neoplasia Outline
• Tumor nomenclature
• Tumor characteris%cs
• Epidemiology
• Cancer pathogenesis
Neoplasia Outline
• Tumor nomenclature
• Tumor characteris%cs • Differen%a%on and anaplasia • Rate of growth • Local invasion • Metastasis
Neoplasia Outline
• Tumor nomenclature
• Tumor characteris%cs • Differen%a%on and anaplasia
Differen%a%on and Anaplasia
• Differen%a%on = how much the tumor cells resemble their cells of origin • Well-‐differen%ated: closely resembles • Moderately-‐differen%ated: sort of resembles • Poorly-‐differen%ated: doesn’t resemble
• Benign tumors are usually well-‐differen%ated
• Malignant tumors can show any level of differen%a%on
Thyroid adenoma (well-‐differen%ated)
Squamous cell carcinoma, well-‐differen%ated
Squamous cell carcinoma, moderately-‐differen%ated
Squamous cell carcinoma, poorly-‐differen%ated
Intercellular bridges
Anaplasia: a state of complete un-‐differen%a%on
• Literally, “to form (-‐plasia) backwards (ana-‐)”
• Misnomer! Cells don’t de-‐differen%ate.
• Just means cells are very poorly-‐differen%ated
• Almost always indicates malignancy
Anaplas%c cells show:
• Pleomorphism
• Hyperchroma%c, large nuclei
• Bizarre nuclear shapes, dis%nct nucleoli • Lots of mitoses, and atypical mitoses
• Architectural anarchy
Anaplas%c carcinoma
Abnormal mitoses
Dysplasia = disorderly (dys-‐) growth (-‐plasia)
• “Dysplasia” is used to describe disorderly changes in non-‐neoplas%c epithelial cells
• Graded as mild, moderate or severe • Mild-‐moderate: usually reversible • Severe: usually progresses to carcinoma in situ (CIS)
• Next step a*er CIS: invasive carcinoma
Dysplas%c cells show:
• Pleomorphism
• Hyperchroma%c, large nuclei
• Lots of mitoses
• Architectural anarchy
Q. Wait a minute, “dysplasia” sounds suspiciously similar to “differen%a%on” – what’s the difference?
Q. Wait a minute, “dysplasia” sounds suspiciously similar to “differen%a%on” – what’s the difference?
A. Both terms describe whether cells look normal or not!
But:
• “Differen%a%on” is only used with neoplas%c cells, and “Dysplasia” is only used with non-‐neoplas%c cells!
• “Dysplasia” is only used with epithelial cells, but “Differen%a%on” can apply to any cell type.
mild dysplasia
moderate dysplasia
severe dysplasia
well-‐differen%ated
moderately-‐differen%ated
poorly-‐differen%ated
anaplas%c
carcinoma in situ
Non-‐neoplas%c epithelial cells
Neoplas%c cells
Dysplasia
Normal glands
Normal gland
Mild dysplasia
Moderate dysplasia
Severe dysplasia
Normal squamous epithelium
Moderate dysplasia Severe dysplasia
Normal epithelium Dysplas%c epithelium
Invasive squamous cell carcinoma
Neoplasia Outline
• Tumor nomenclature
• Tumor characteris%cs • Differen%a%on and anaplasia • Rate of growth
Generaliza%ons about Growth
• Malignant tumors grow faster than benign ones.
• Poorly-‐differen%ated tumors grow faster than well-‐differen%ated ones.
• Growth is dependent on: • Blood supply • Hormonal factors • Emergence of aggressive sub-‐clones
Growth Frac%on
• GF = % of tumor cells that are dividing
• Age of tumor mabers • Early on (subclinical), GF high. • Later (clinically detectable), GF low.
• Type of tumor mabers • Leukemias, lymphomas, small-‐cell lung cancer: high GF • Breast, colon cancer: low GF
• Important for treatment • High GF tumor: treat with chemotherapy/radia%on • Low GF tumor: treat by debulking
Tumor cells undergoing apoptosis
Neoplasia Outline
• Tumor nomenclature
• Tumor characteris%cs • Differen%a%on and anaplasia • Rate of growth • Local invasion
Local Invasion
Benign tumors • Stay where they are. • Can’t invade or metastasize. • Usually encapsulated.
Malignant tumors • Infiltrate, invade, destroy surrounding %ssue. • Then metastasize to other parts of body. • Not encapsulated.
Malignant tumor invading kidney
Malignant tumor invading kidney
Malignant tumor invading kidney
Neoplasia Outline
• Tumor nomenclature
• Tumor characteris%cs • Differen%a%on and anaplasia • Rate of growth • Local invasion • Metastasis
Carcinoma in situ
Invasive carcinoma
Invasive carcinoma
Metastasizing carcinoma
Liver with mul%ple metastases
Metastasis
• Metastasis = development of secondary tumor implants in distant %ssues
• Half of all pa%ents with malignancies have mets at the %me of diagnosis!!
• Metastasis depends on: • Type of tumor • Size of tumor • Degree of differen%a%on of tumor
Three Ways Tumors Metastasize
• Seeding • Lympha%c spread
• Hematogenous spread
Three Ways Tumors Metastasize
• Seeding • Tumor invades body cavity • Bits break off and implant on peritoneal surfaces
• Ovarian cancer can spread easily this way
Liver seeded with metasta%c ovarian carcinoma
Three Ways Tumors Metastasize
• Seeding • Lympha%c spread
• Tumor spreads to local lymph nodes • Sen%nel lymph node first • Moves through thoracic duct • Emp%es into subclavian vein • Carcinomas like to spread this way
Tumor in lympha%c
Tumor in lymph node
Tumor in lymph node
Three Ways Tumors Metastasize
• Seeding • Lympha%c spread
• Hematogenous spread • Veins are easier to invade than arteries • Liver and lungs are the most common metasta%c des%na%ons
• Sarcomas like to spread this way (but so do carcinomas)
Sarcoma metasta%c to lung
Sarcoma metasta%c to lung